KIEV (Reuters) - A dangerous culture of impunity flourishes in Ukraine where arbitrary killings by Ukrainian forces or separatist groups are rarely prosecuted, a United Nations human rights report said on Thursday.

Over 9,400 civilians, government soldiers and Russian-backed rebel fighters have been killed in Ukraine since a 2013-2014 pro-European uprising in Kiev sparked a separatist conflict in eastern regions of the country.

The U.N. report, the first of its kind since the start of the fighting, focuses on alleged summary executions and arbitrary killings in the conflict zone carried out while no armed hostilities were taking place in the immediate vicinity.

It highlights the danger posed by the lack of accountability for unlawful killing as fighting rumbles on in the war-torn east despite a ceasefire declared nearly 18 months ago.


"There has been no accountability for the vast majority of alleged summary executions and killings committed in the conflict zone," said the report by the Office of the United Nations High Commissioner for Human Rights (OHCHR).

"Impunity for killings remains rampant, encouraging their perpetuation and undermining prospects for justice," it said.

It reported incidents of alleged arbitrary killings both by pro-Russian separatist groups and by Ukrainian troops, law enforcement officers and volunteer battalions in the conflict zone.

Some perpetrators have been brought to justice, OHCHR said, but investigations and prosecutions are often drawn out or stalled entirely.

"OHCHR has observed an apparent lack of motivation to investigate in some cases ... especially when it concerns acts allegedly committed by Ukrainian forces. Cover-up and political bias are not uncommon," it said.

In rebel-controlled territory, investigations appeared to be selective and did not guarantee fair trial, the report said.

In an annexe to the report it said was far from exhaustive, OHCHR listed 60 cases it has verified from January 2014 to May 2016. These included the alleged killing of surrendered soldiers or fighters, the torture and violent deaths of individuals in captivity and the alleged execution of 58 people.

"Relatives of victims are often the ones urging authorities to initiate an investigation. In some cases law enforcement officials only register the case ... and barely carry out any investigative actions on various pretexts," the report said.

(Reporting by Alessandra Prentice; Editing by Tom Heneghan)